Electric regulator



Dec. 19, 1922.

1,438,945. n. 0. CONWAY.

ELECTRIC REGULATOR. FILED JULY 24, 1919.

//7ve/7f0r: By D. Conway Patented Dec. 19, 1922.

UNITED STATES PATENT OFFICE.

ROY D. CONWAY, OF CHATHAM, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED OF NEW YORK.

YORK, N. Y., A CORPORATION OF NEW ELECTRIC REGULATOR.

Application filed July 24,

To all 'Uf ibOfil '1' t may concern Be it known that I, Roy D. CONWAY, a citizen of the United States, residing at Uhathani, in the county of Morris, State of New Jersey, have invented certain new and useful Improvements in Electric Regulators. of which the following is a full. clear, concise, and exact description.

This invention relates to arrangements for regulating an electrical characteristic of a circuit such as the intensity of current flowing therethrough.

()ne ot the objects of this invention is to provide means for insuring a How of current of constant intensity over a circuit. Another object consists in providing means for auto- 'matically increasing the resistance in a circuit whenever the current flow therethrough has a tendency to increase, and means for automatically reducing the resistance as the current flow decreases. A further object consists in the provision of means for cutting in or out resistance in any circuit by successive steps in order to hold constant an electrical characteristic in a portion of the circuit. Other objects of this invention will appear in the detailed description to be given later.

It is often found desirable to associate with a work circuit includingtranslating devices such, for example, as a circuitincluding the filament of a vacuum tube repeater, an arrangement for regulating the current flow therethrough. This is because the voltage at the source supplyingthe current in the circuit may have a tendency to vary beyond the limits within which satisfactory operation of the apparatus will result. As it has been found that a vacuum tube repeater will give better service if the current fiow through its filament circuit remains constant, the regulating apparatus comprising this invention has been provided.

The regulating apparatus of this invention includes a voltmeter relay sensitive to slight variations in voltage and whose winding is connected to the source which suppliescurrent for the work circuit. An increase in the voltage of this source will cause a circuit to be closed over the needle and one of the contacts of the voltmeter thereby operating a resistance varying mechanism to add a. certain. amount of resistance in series 1919. Serial No. 313,033.

with the winding of the voltmeter relay, and also in series with the filament contained in the work circuit. If the resistance thus added to the voltmeter circuit and the work circuitis not sufficient to counter-balance the increase in current due to the change in voltage, the voltmeter needle will not fall back to neutral position but will still serve to hold closed the circuit over the contact of the voltmeter. i-\.ccordingly the resistance varying mechanism will continue to operate and will add further resistance units to the circuit including the voltmeter winding and the work circuit until the increase in current How has been counter-halal](red and the needle returned to neutral position.

If the current flow from the source decreases. a circuit is closed over the needle and the other contact of the voltmeter which operates the resistance varying mechanism to reduce the resistance in the voltmeter circuit and the work circuit in proportion to the decrease in voltage.

The resistance varying mechanism comprises a series of relays under the control of the contacts of the voltmeter. The relays of this series are adapted to control the as sociation with the voltmeter circuit and the work circuit of a plurality of resistance units. Means are also provided for insuring the successive action of this series of relays so that only one resistance may be cut in or out of the work circuit and the voltmeter (ircuit at one time. In the preferred form of this invention this is accomplished by employing an interrupter which controls the energizing circuit for this series of relays to open said energizing circuit as soon as one of the resistance controlling relays has been energized or deenergized and closes said cireuit after the addition or subtraction of the resistance in the work circuit has changed the current in the voltmeter circuit to bring the voltmeter needle back to neutral position. However, it the resistance added is not sufficient to bring the needle back to neutral. position an additional resistance controlling relay will be operated as soon as the interrupter has closed the energizing circuit again.

This invention may now be more fully understood from, the following detailed description taken in connection with the acconipanying d fan in w in which Fit. 1 repre" sents the preferred form of the circuit ar- 'einent of his invention and 2 is a ication thereof. heterring to 1, connected to a battery i circuit containing a plurality of nory short-circuiiied resistance units l, 5, l 7 and the Winding of a voltmeter relay resistance units and the battery are included in a circuit Which supplies the :i no; current for a plurality of: filaments inch sire, which may he connected in par lel by groups. The voltmeter relay 8 has a an located between two stationary contacts and 11. Elince these contacts are crtreniely delicate; the needle 9 is connected to an intermediate point of a circuit containing the high resistances 17,18 and ha te y i s that only traction of the total ential of battery 3 he applied to the i iltnieter needle in case the total potential oi? battery 3 would. he injurious to the con tacts it applied directly.

Under the control of the voltmeter needle 9 an i contact 10 is a relay 52.0 which. through the intermediary oi the movable contacts of a relay 521 serves to control the energizetion oi the series ot relays to inclusiye. The energization of this series of relays .452 inclusive serves to open the short circuits around r sistances to 'Z inclusive, thereby adding these resistances l to 7 inclusive to the cuit including the Wind inn" oi voltmeter relay 8 ant. the filaments 9- i inclusive of the aiuni tube repeaters. The resistances -1l-"? inclusive have a Value predeterniii d with respect to the :uljustincni'; of the contacts of the voltmeter relay El. fin interrupter 28, by periodically opening; and closing the enerrizinp; circuit o i? relay 2i insures that the r s to 2 inclusive will he operated. successivelyand that there will he no surging of current therein. Under the control of needle 9 andv contact ll. a relay which, through the intermediary oi? the movable contact of a relay 3]. serves to control the deenerggization of relays 25') to 25 inclusive to suht act the resi nce elements 4-? inclusive from the voltineter and the Work circuit. The successiye d energization of the relays 22-25 inclusive secured by the ope 'ation of the i 28.

current supplied to the Work I may he necetsary to contional re. ay 33 ii tl rela to ground. The heatcircuit tor the filaments i to l-l inclusive is traced ir ground, hattcry -3 the nt paths for RBSVUYMJCS i to "l inclusive,

ahoye, conductor 1, through the lilaground. in increase in the voltage ot' source Will he ilk limited. by a deflection to the rig; t of the needle oil? the voltmeter 8 thereby closing the tollowingcircuit from ground" battery 3.. resistance .8 needle 9, contact ll), Winding; otrclay 20 to ground. The closing of shove desci hed c'rouit cnm'giv-es relay 2,0 which pulls up its inovahle co cts l6, 4:7, and closes i movable conta-t 16, Windingof relay 21, inoraole contact and "minding of interrupter 28, to battery and ground. The energgization of relay 2i will cause its movable contact to h pulled over and close the folloivinn; circuit "nn grmind niovahle con flip l RAJU tact 4-7 of relay 20, movable contact 49 0'? Y 21. conductor 50. winding of relay 2E2 meter circuit may then be traced. as folloivs--grounth battery 3 resistance 4:, shunt iaths :tor resistances a, 6 and l and conductor .i-J... i he closing of the r orahle contact 51 of relay locks relays 2:2, and ill-l over the fol lowing; circuit; from grounth battery 3, relay Shand from ground, battery relay 22 through movable contact 51, conductor 53, conductor 54, movable contact of relay 30, to ground. Thus it is seen that the operation of relays u a u. hare added resistance 4; to the WOllI suit to count alancc the increase in the voltage of source 8, thereby tending to prevent an increase in the heating current for c :e ivorlr circuit.

lit the addition ct resistance t to the Work circuit and the voltmeter circuit is sutiicient to counterbalance the increase in the voltage o't source 3. the voltmeter needle 9 will r turn to neutral position and open the circuit formerly closed. throiuzh the winding of relay 20, thereby deenero'izing relay 2-0 which allows its movable contacts to all hack. 1 he the following circuit from round,

operation of the interrupter or self-interrupted relay 28 should be so timed that when, as just 'assumedfthe addition of one resistance is sufficient to counter-balance an increase in voltage of the source 3, relays 20, 21, 22 and 33 will have operated and the voltmeterneedle 9 'will have fallen back to neutral position before the self-interrupted relay 28 will have had 'timeto attract its movable contact 48 and break the energizing circuit for relay 22,previously traced. \Vith the self-interrupted relay 28 timed in such a manner, the voltmeter needle, as described above, will fall back to neutral position thereby deenergizing -relay 20. The deenergization of relay 20 will then break the circuit containing the winding ofrelay 21, the movable contact and the winding of the selfinterrupted relay 28, before this self-interrupted relay has had time to attract its movable contact to open the circuit. In the pre ferred arrangement this self-interrupted relay should be adjusted to open the circuit from four to sixteen times a second.

If the addition of resistance 4 not suiiicient to counter-balance the increase in the voltage of battery 3, the needle of the volt meter relay will not return to 'neutral position, but will remain deflected to the right and the relay 20 will remain energized and keep its movable contacts pulled over. As soon as sufiicient time has elapsed after the energization of relay 20, the self-interrupted relay 28 will attract its movable contact 48 thereby opening the following circuit; ground, movable contact 46 of relay 20, winding of relay 21, movable contact 48, winding of relay 28 to battery and ground. The opening of thiscircuit will deenergize relay 2].. which will allow'its movable contact 49 to fall back andv close the following circuit; ground, movable contact 47 of relay 20, movable contact 49, conductor 56, movable contact'57, conductor 58, winding of relay 23, to battery and ground, and conductor 59, winding. of relay 34, to battery and groundv This will energize relays 23 and 34 to close their movable contacts and lock relays 23 and 34 over the following circuit; from ground, battery, winding of relay 34, conductor 59, and grounrhbattery, winding of relay 23, through movable contact 61, conductor 62, conductor 64, movable contact 66 of relay 31 to ground. The attraction of the movable contacts of relay 3.4 and movable contact 39 of relay 23 will open the shunt paths around resistance 5 thereby inserting this resistance in the work circuit and the voltmeter relay circuit. The operation of relay 23 also breaks the locking circuit for relays 22 and 33,- previously traced, and removes them from under the control of relay 30 by locking them over the following circuit; ground, battery. winding of relay 33, and ground, battery, winding of relay 22, movable contact 51, conductor 53, movable contact 70, to ground. Thus it is seen that with the operation of relay both resistances 4 and 5 are included in the voltmeter circuit and the work circuit.

If the addition of resistance to the voltmeter circuit is sufficient to counter-balance the increase in the voltage of battery 3, the voltmeter needle 9 will fall back to neutral position thereby deenergizing relay 20 before suflicient time has elapsed for the previously deenergized self-interrupted relay to allow its movable contact to fall back and complete the circuit through the winding of relay 21.

If the addition of resistance 5 is not sufficient to countor-balance the increase in the voltage the voltmeter needle will not return to neutral position, but will remain deflected to the right, thereby keeping closed the movable contacts of relay 20. As soon as sufficient time has elapsed, the movable contact 48 of the self-interrupted relay 23 will fall back and complete the energizing circuit previously traced for the winding of relay 21. This will energize relay 21 which will pull over its movable contact 49 and close the following circuit; ground, movable contact 47, movable contact 49, conductors 50 and 72, movable contact 73, Winding of relay 24, to battery and ground, and winding of relay 35, to battery and ground. Relays-24 and 35 will. then attract their movable contacts and become locked up over the following circuit; ground, battery, winding of relay 35, and ground, battery, winding of relay 24, movable contact 74, conductor 75, conductor 54, movable contact of relay 30, to ground. The attraction of the movable contacts of relay and the movable contact 41 of relay 24 will open the shunt paths for resistanceli thereby inserting the resistance 6 in the voltmeter circuit and the work circuit. The operation of relay 24 also breaks the locking circuit for relays 23 and 34, traced above, and removes these two relays from under the control of the movable contact of relay 30 by locking them over the following circuit; ground, battery, winding of relay 34, and ground, battery, winding of relay 23, movable contact 61, conductor 62, movable contact 80, to ground. Thus it is seen'thatwith the operation of relays 24 and 35, resistances 4, 5 and 6 are included in the voltmeter circuit and the work circuit.

If the addition of resistance 6 is sufficient to counter-balance the increase in voltage of source 3, the voltmeter needle 9 will return to neutral position, deenergizing relay 20 before sufiicient time has elapsed for the selfinterrupted relay to attract its movable contact and break the energizing circuit for relay 21. i

However, if the additionof resistance 6 is 'trol of the movable contact oi.

X in voltage of source the .ucc lls: will remain nlenecterl tkeeping th contacts or is soon as sutlicient time sell?-ii'iterrupterl movable ctntact e energizing circuitenergioation of relay able contact to fall back and lou'iu- Cldlll'il," ground, more Jle con of rela T 20, inovablc contact l-Q. courln -to movable cc i rehav :2 battery and ground, ane 36, to l Ty and ground. this circuit will energize relays 2! anrl so that they will pull up their movable contacts and become locked up over the 'l lloiving circuit; ground, batt winding clay 86, and ground, battery, Winding or relay movable contact conductor G l, u'zovable contact 66 oil relay ill. in gggrounrli i l-- traction of the movable contacts of re and the movable contact T oli relay 525 i, :i i open the shunt paths around resistance thereby inserting this resistance in the \vorl. circuitand the voltn'ietc clrwuit. T he operation of relay also breaks the locking circuit of relays 2s; and 85, traced all; removes these two rel ys from out ior b locking them up over the follow 'I J 1 1 VJ l cult; grouno, artery, llllllgalllg 0:6 I and ground, battery, Winning oi: relay 2*, movable contact "a l, conductor 75,1uovable contact 89 to ground It the aclzlition of resistance J to tle voltm s suns meter circuit and the work circuit i cient to counter-balance the incre e voltol source 3, the voltmeter neeule will re turn to neutral position thereby (lecnergizing' relay 9 before sufiirient time has elapsed I For the interrupted relay 28 to operate" ll hile the series of relays which control the amount of resistance in the volti'neter circuit and the wort: circuit is shown consisting of only four relays 522 to 25, inclusi anti their associated resistance elements, it will. be understo cl. that this series is not limited to any specific number, but that any desirable number of such relays and resistance ele-- ments maybe incluclerl. in the circuit arrangement of the regulator. this means any rise in voltage which may be encountcrei can be compensated :tor so as to limit the current flow and the current flow can be helrl Within any desirable llHlllJS by a suitable number of relays controlling resistance e cuts.

The operation of this inven n :tor aider-rease in voltage may be explained :ltollows: If for example, after the rise in voltage at the source 3 has been counter-balanced by the operation of relays to 25, inclusive, and the subsequent addition to the Work circuit and the voltmeter circuit of resistances l we should start ;o tall, tineter Will be deflected and close the :lollo'wing circuit;

l, battery 3, r st nce needle 9, contact 11, winding or" rel 'lhe closii o" L iis circuit W1 L lay Whicn will pull over its i tact and close the following ground, movable contact 'WlIlCllil'L i rela" oat, anal conuu tor 54,

by he pullin ig up of movable contact 55 will not r s urb in any Way the snow zine circuits r .31 w for relays 9,2 to inclusive, since the operation of relay 2., previously described, 1 lIiO'VBll 2s from the control of this able contact. ltelay 31 will pull over movable contact 86 thereby opening the following circuit; ground anrl inevaole cont-ct (iii conductor 64-, niovable contact 8'? ol. relay 25, winding of? relay 25, to battery an l I 'ounzl and the Winclirg of relay 3G to bat -y aiul ground, The breaking of this cir r-uit will (leenei r se relays 25 and. -which Will allow their movable contacts to fall back and close the shunt paths for resistance 7, thereby decreasing; the resistance in the Work circuit, l /ith the cleenei'gization of relay the lo lung circuit for relays .Z l and 35 which were previously locked through 1110K?- able contact 89 of relay 25 to ground, will be chan 'ecl to the following circuit unrler the 1 ol movable contact '66 of relay i: our ground, battery, winding oit relay 35, and ground, battery, "inhaling of. relay 24;. inovable contact M of relay 24L, conductor 45, conouctor 541;, movable contact of ener- ,Q'lZCfl relay El, to ground. At the same ti'n'ie relays 2F and 56 will be out uniler cm rontrol of relay 20 by the connei tion (it their winilii "s through movable contact 84: of lay to conductor v If the subtraction ct r r sistance 7 from the voltn'ieter circuit is sullicient to compensate for the rlecrease in rolta ge oft soul-kc 3, the neerllc of the voltmeter will return to neutral position to (leenerg ize relays 30 and 31 be- :lore the selt-interrupteil relay 28 has had sul'hcient time to op rate. l l ith the zloenergrizt tion of relays anal 3. the locking cirunit for relays anr v A l nuclei the control of relay 30 on ccount of the talling back 01 lovable cents. it 05 and if}, and tracecl as follows: from. ground, movable contact conductor 54:, conductor 75, movable contact '1 e, winding 01": relay A to battery and ground, ancl Winding of relay 35 to battery ground.

lilo vever, if tl e subtraction or resistance 7 is not sulllcient to counter-3a not: the (learease in voltage of source3, the needle 01" the voltmeter Will remain deflected to the left and keep energized relays 30 and 31. The locking circuit for relays 24 and 35 therefore will remain under the control of movable contact 66 of energized relay 31 instead of having the locking circuit changed so as to terminate in the movable contact 55 of relay 30 described above in the case where the addition of relay 7 was sufficient to bring the voltmeter needle back to neutral position. As soon as sufiicient time has elapsed the self-interrupted relay 28 will attract its movable contact and open the following circuit; ground, battery, winding of relay 28, movable contact 48, winding of relay 31, movable contact 55 of energized relay 50, to ground. The opening of this circuit will deenergize relay 31 thereby allowing movable contact 66 to fall back. The falling back of movable contact 66 will break the following circuit; ground, battery, winding ot relay 35, and ground, battery, winding of relay 24., movable contact 74, conductors 75 and 54, movable contact 66, to ground. The opening of this circuit will deenergizerelays 24 and 35, thereby allowing their movable contacts to fall back and close the shunt paths for resistance 6. The deenergization of relay 24: places relay 24 under the control of relay 20 by the following connection to the main conductor 72 so that in case the voltage should subsequently rise in value, relay 20 will operate to reenergize relays 24 and 35; from ground, battery, winding of relay 24, movable contact 73 of relay 23 to conductor 7 2. Before relay 24 was deenergized, relays 23 and 34 were locked up over the movable contact 80 of relay 2% But after the deenergization of relay 24 their locking circuit is changed to the following circuit; ground, battery, winding of relay 23, and ground, battery, Winding of relay 34, movable contact 61 of relay 23, conductors 62 and (34, movable contact 66, to ground.

If the subtraction of resistance 6 is sufficient to counterbalance the decrease in voltage, the voltmeter needle is returned to neutral position and relay 3O deenergized before suflicient time has elapsed for the movable contact of relay 28 to fall back and reener- ,gize relay 31.

However, if the subtraction of resistance 6 is not sufficient to counterbalance the decrease in voltage, the volt-meter needle will remain deflected to the left, thereby keeping relay 30 energized. As soon as sufficient timehas elapsed for the movable contact 48 to fall back to close the energizing circuit for relay 31, relay 31 will-attract its armature 66 and break the locking circuit previously described for relays 23 and 34. The deenergization of these relays will close the shunt paths for resistance 5, will connect their windings to the conductor 56 so as to place themselves under the control of relay 20 for a subsequent increase in voltage, and will also transfer the locking circuit for relay 22 to the control relay 250.

II" the subtraction of resistance 5 is not sufiicient to counterbalance the change in .oltage, relay 31 will be deenergized by the operation of self-interrupted relay 28 and break the locking circuit of relays 22 and thereby short-circuiting resistance 4.

Thus, it is seen that at any given time in the operation or this invention only one relay oi series 22 to 25, inclusive, is under the cont'ol of the leit contact of the voltmeter rel. y and only one oi the series is under the control or the right contact of the voltmeter relay. If, for example, a certain change in voltage has occurred to operate relays 22 s 24-. and are still deener a. aid be under the control 0 contact ii of the voltmeter while relay would be under the control of the contact 10 of he v ltmeter, thus providing means tor counter-billancing a further increase in volage or a decrease in voltage.

Il ig. 2 illustrates a modil *ation that may be made in l. by the sui itution for the self-interrupted re"y 28, of a motor-driven errupter 95 which may be operated continuously to make and break the circuit connections between ground, battery 3, contact 96 of the interrupter and the windings of relays 2i and 31. The operation of the circuit arrangen'ient with the motor-driven inand, win

terrupter similar to that described above.

w th the s i-interrupted relay, the only difference being that the selt-interriuited relay operates to make and break the circuit connectioi'is to the windings oi? relays 21. and 31 only when relay 20 or relay 30 is energized while the motor-driven interrupter will operate to make and break the circuit independent oi the 'em'rgization oi? relays 20 and 30.

\Vhile this invention has been disclosed in particular forms which have been found do sirable, it will be understood that it may be embodied in many and widely different forms without departing from the spirit or" this invention. as defined in the appended claims.

What is claimed is:

1. The combination of a solenoid, a plurality of resistance elements for connection in or out of circuit with said solenoid, relays individual to said resistance elements for controlling said elements, and means comprising an interrupter to; placing said relays under the control oi said solenoid.

2. The combination oi? a solenoid, a work circuit, a plurality of resistances in said work circuit controlled by said solenoid, movable contacts individual to said resistances, and means comprisin an interrupter for causing said movable contacts to be controlled by said solenoid.

3. A regulator comprising a solenoid, a

source of voltage, a plurality of impedance elements, a circuit containing said solenoid, said source or voltage and said impedance elements, shunt paths for said elements, and means comprising an interrupter and a relay responsive to said solenoid for controlling said shunt paths.

an regulator comprising an electror sponsive device, a source or voltage, a plurality of impedance elements, circuit containing said devic said source of voltage, and said impedance elements, shunt paths for said elements, means comprising an interrupter and a relay responsive to said de rice for controlling said shunt paths for an increase in voltage of said source, and means on imi'ising interrupter and a second relay responsive to said device for controlling said shunt paths for a decrease in the voltage oi said source. s regulator c mprising an electrore- 0. ii sponsive device, source or voltage, a plurality of regulating elements, a circuit containing said device, ,aid source of voltage and said regulating elements, one of said regulating elements being normally under the control of said device, means comprising an interrupter for placing another oi said elements under the control oi said device.

6. l regulator comprising a voltmeter, a source of voltage, a plurality of resistance elements, a circuit containing said voltmeter, said source of voltage and said resistance elements, one cl? said resistance elements being norn ally under the control of said voltmeter, and means comprising a continuously operating interrupter for placing another of said elements under the control of said voltmeter.

7. in a system of distribution, a source of voltage, a volti'i'icter, a plurality of impedance elements, a circuit containing said volt meter, said source voltage and said impedance elements, shunt paths for said impedance elements, means responsive to an increase in voltage for controlling the openof one of said shunt paths, and means responsive to a decrease in voltage for controlling the closing of one of said shunt paths, each 1 said means comprising an interrupter.

ln a system of distribution, a source 01? voltage, a plurality of resistance elements. a work circuit containing said source of voltage and resistance elements, and means for holding substantially constant the (nu-rent l1, said work circuit, said means comprising a voltmeter associated with said worl: circuit and means comprising an interrupter, and plurality of relays responsive to said voltmeter for effectively discon necting said resistances from said work circuit, and a plurality of relays :tor subsequently connecting said resistances in said work circuit.

9. In a system of distribution, a source of voltage, a plurality of resistance elements, a work circuit containing said source and said resistance elements and means for controlling the current in said work circuit, said means comprising a voltmeter associated with said work circuit, shunt paths for said resistance elements, an interrupter, a relay responsive to said voltmeter, a set of relays comprising a relayindividual to each of said shunt paths, said set being responsive to said first relay only when said inteisupter op 'erated.

10. A regulator con 9 'lsing a voltmeter, a plurality of regulating elements, a solenoid, an energizing circuit for said SOl11Ol ,D1e2tl1S responsive to said voltmeter ror closn r sail ene gizing circ one Oi said :i' .i ulatincj ment normally under the control of sail soleno 7., for periodically opening and closing said energizing circuit after said voltmeter has operated to close said circuit, said means operating to transfer the control oil said solenoid to another said regulating elements,

ln system of distribution, a source of voltage, a work circuit comprising said source, means for holding substantially constant the current in said circuit, said means comprising a voltmeter responsive to a condition of said circuit, a plurality resistance elements in said circuit, a solenoid, an energizing circuit for said solenoid, means responsive to said voltmeter for closing said energizing circuit, one of said resistances being normally under the control oi? said solenoi l, means for periodically opening and closing said energizing circuit after said voltmeter has operated to close said circuit, said means operating to transfer the control oi? said solenoid to another of said resistances.

12. A regulator comprising a voltmeter, a plurality oi resistance elements, shunt paths individual to said resistances normally closed, a solenoid, an energizing circuit for said solenoid, said solenoid normally controlling the shunt path for one of said resistances, means responsive to said voltmeter for closing said energizing circuit, and means for periodically opening and closing said energizing circuit whereby said solenoid opens one of said shunt paths when said energizing circuit is closed, opens a second of said shunt paths when said circuit is opened and opens a third of said shunt paths when said cult is closed again.

1] 3. in a system of distrihiition, a source of voltage, a voltmeter having a winding, a plurality o'l resistances, shunt paths for said resistances, a circuit containing said source, said resistances and said winding, a work circuit containing said source and said resista ces, an automatic means responsive to changes in voltage of said source for controlling said shunt paths to regulate said Work circuit While maintaining substai'itiaily constant the calibration of said voltmeter.

14'. In a system of distribution, a source of voltage, a voltmeter having a Winding, a plurality oi resistances, a circuit containing said source, said resistances anu said Winding, a work circuit containing said source and said resistances, means comprising a series oi relays responsive to changes in volta e of said source for controlling said resices to hold substantially constant the current in said work: circuit While maintaining constant th 1 calibration oi said VOlLillGlLQl.

'r-in of distrilimtion. a source oi? :tmeter having a mg, a pinrality or resistances, a circuit containing said source, r 'stances and said winding, a Work circuit conttsning sa source and said resistances, a; means comprising relay responsive to v s in. voltage oi. said sourc :i or contrc ng one of said resistances to vary the calibration of said voltmeter, and to regulate said Work circuit, and means comprising an interrupter tor transi erring the control of said relay to another of said resistances.

16. The combination o? a circuit to be regulated, regulating elementstherefor, f electroresponsive device for said circuit, C!:'- cuit connections for said regulating elements, means comprising a series of relays for controlling said circuit connections, and means comprising a continuously operated interrupter for placing said relays under the control of said device, said interrupter operating independently of the condition or the circuit to be regulated.

li'. In an tric system, series of several solenoids, a master solenoid, connections dependent upon the energization of said Inaster solenoid for succes ively controlling alternate solenoids of said series, and connections dependent upon the deenergization of said master solenoid for controlling the other solenoids of said series.

18. In an electric system, a work circuit, a series of several regulating elements in said circui a solenoid responsive to a condition of said circuit, coi'inections dependent upon the energiaaa of said solenoid tor successiveig, controlling alternate elements 0i said series, and connections dependent upon the deene 'ation of said solenoid lor controlling the remaining elements or said series.

In combination, a translating device, a solenoid, a series of several regulating elements, said device, said solenoid and said elements being so connected in circuit that said ments are in series with said solenoid and device in parallel, connections dependent upon the energization of said solenoid for successively controlling alternate elements of said series, and connections dependent upon the deenergization of said solenoid for controlling the remaining regulating elements.

In witness whereof, I hereunto subscribe my name this 21st day of July A. D., 1919.

ROY D. CONWAY. 

